Help me with Emacs

["Ronit Tajian" <rtajian@hotmail.com>]

Hi,
I downloaded Emacs 21.4 from ftp://ftp.gnu.org/gnu/emacs/emacs-21.4a.tar.gz 
under Linux.

Followed the instructions in the INSTALL text to install it. Everything 
seems to went fine. When trying to run or open the Emacs receive this error:
---------------------------------------------------------------
Xlib: connection to ":0.0" refused by server
Xlib: No protocol specified

emacs: Cannot connect to X server :0.0.
Check the DISPLAY environment variable or use `-d'.
Also use the `xhost' program to verify that it is set to permit
connections from your machine.
-------------------------------------------------------------------------------------

Not sure what the problem is. When open the Emacs like this, a window opens, 
but the menu on top is not available and when closing the Emacs window it 
closes the whole X window.
However, from my bash console, I can easily open an X window using xterm 
command, the X window opens with no problem, but running the Emacs rises the 
above error. Please let me know of any idea.

Thanks,
Ronit